Each year more than 750,000 Americans suffer a stroke. Strokes are often caused by unhealthy cholesterol levels. Cholesterol is a waxy substance that circulates, but does not dissolve, in the blood. If a person has too much low-density lipoprotein (LDL), also known as bad cholesterol, it can slowly build up in the wall of the arteries. Eventually this buildup forms a thick, hard plaque that narrows the arteries. If one of these plaques ruptures, it causes a blot clot to form, which can block normal blood flow to the brain and lead to a stroke.A stroke is a sudden disruption in blood flow to the brain caused by a blockage or bleeding of a blood vessel. Areas of the brain that are affected by the blockage or bleeding can become damaged within minutes.The effects of a stroke may be mild or severe and temporary or permanent, depending on which brain cells are damaged, how much of the brain is involved, and how quickly the blood supply is restored to the area.Symptoms of a stroke are sudden and may include:Numbness, weakness, or lack of movement (paralysis) in the face, an arm, or a leg, especially on only one side of the body.Trouble seeing in one or both eyes.Confusion and difficulty speaking.Dizziness and a loss of balance or coordination.Vomiting.A sudden, severe headache.A person with stroke symptoms needs immediate medical attention to help limit potential damage.